In gas turbine engines to which the invention disclosed herein applies, fuel is burned within a combustion chamber to produce a hot effluent. The effluent is expanded within a turbine section across alternating rows of stationary stator blades and rotating rotor blades to produce useable power. Effluent temperatures at the initial rows of vanes and blades commonly exceed two thousand degrees Fahrenheit (2000.degree. F.) (1093.3.degree. C.). Blades and vanes susceptible to damage by the hot effluent are cooled by air compressed upstream within the engine and flowed to the turbine for cooling.
One substantial problem associated with such systems is the transfer of cooling air from stationary cavities within the engine stator to the rotor assembly for subsequent distribution to the interior of the rotor blades. U.S. Pat. No. 3,768,921 to Brown et al. entitled "Chamber Pressure Control Using Free Vortex Flow"; U.S. Pat. No. 3,990,812 to Radtke entitled "Radial Inflow Blade Cooling System"; U.S. Pat. No. 4,178,129 to Jenkinson entitled "Gas Turbine Engine Cooling System"; U.S. Pat. No. 4,236,869 to Laurello entitled "Gas Turbine Engine Having Bleed Apparatus With Dynamic Pressure Recovery"; and U.S. Pat. No. 4,435,123 to Levine entitled "Cooling System for Turbines" disclose concepts related to the present invention for effecting such distribution.
Notwithstanding the availability of such concepts, scientists and engineers within the gas turbine industry have continued to search for yet improved concepts, and particularly for concepts making more judicious use of cooling air supplied or reducing supplied airflows which are in excess of that required.